Ablative materials have been used in a variety of applications to protect and insulate structures subjected to extreme thermal conditions. For example, many aerospace vehicles that traverse, exit, and enter the atmosphere of the Earth travel at high velocities, and as a result, their exterior aerosurfaces, and to some degree their substructure, experience high aerothermal loads. Aerothermal loads have been managed using a variety of techniques including insulation, radiant cooling, active cooling, conduction and convective cooling, and by phase change or ablative materials. Generally, ablative materials are applied to the affected aerosurfaces to absorb the extreme heat in order to insulate the vehicle from the thermal environment.
Known ablative materials comprise a variety of constituent components, each at certain percentages by weight or volume, to achieve a balance of thermal protection and other physical properties. Generally, ablator compositions are a composite material comprising a resin matrix with a variety of filler materials to reduce the overall density or provide other physical properties.
Known ablative materials typically have performance envelopes in which these known ablative compositions perform effectively. When exposed to heating or pressures in excess of these envelopes these known ablative compositions can erode rapidly, requiring excessive thickness (weight) of the material. When used in more benign environments, these known ablator compositions function as poor insulators, also requiring additional thickness.
Accordingly, there remains a need in the art for an ablator composition that is of low-density yet has high erosion resistance and durability before, during, and after high thermal loads, and which is relatively low cost and simple to fabricate.